宇宙科学広報・普及主幹付

矢治 健太郎

ヤジ ケンタロウ  (Kentaro Yaji)

基本情報

所属
国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 火星衛星探査機プロジェクト 主任
早稲田大学 教育学部 非常勤講師
学位
修士(学術)(1993年3月 東京大学)

研究者番号
10399305
J-GLOBAL ID
200901049288017724
researchmap会員ID
6000020477

外部リンク

1991年 東京大学教養学部基礎科学科第二 卒業
1993年 東京大学大学院総合文化研究科広域科学専攻修士課程 修了
1996年 総合研究大学院大学博士課程数物科学研究科天文科学専攻 単位取得満期退学

1996年4月から2004年3月 和歌山県の公開天文台・かわべ天文公園で主任研究員・天文台長を務める。天文教育普及活動を行う。
2001年6月に明星大学ザンビア皆既日食隊に参加。
2002年10月 小惑星「Yaji」(登録番号7956)命名される。
2004年7月から2005年10月 国立天文台天文学データ解析研究センター・Solar-B推進室にて研究支援員。
2005年11月より、立教大学プログラム・コーディネーター。現代GP「理数教育連携を通じたCBLSプログラム」を推進する。
2008年4月より、立教大学理学部共通教育推進室 特任准教授
2014年4月より、国立天文台・太陽観測所 専門研究職員
2017年4月より、国立天文台・太陽観測科学プロジェクト 専門研究職員
2018年4月より、杉並区立済美教育センター 理科指導員
2018年10月より、自然科学研究機構核融合科学研究所・研究力強化戦略室 URA職員(特任専門員)
2023年9月より、現職

専門は太陽物理学・天文教育・科学コミュニケーション。


主要な論文

 33
  • SAKURAI Takashi, HANAOKA Yoichiro, HANAOKA Yoichiro, ARAI Takehiko, ARAI Takehiko, HAGINO Masaoki, KAWATE Tomoko, KAWATE Tomoko, KITAGAWA Naomasa, KITAGAWA Naomasa, KOBIKI Toshihiko, MIYASHITA Masakuni, MORITA Satoshi, OTSUJI Ken’ichi, OTSUJI Ken’ichi, SHINODA Kazuya, SUZUKI Isao, SUZUKI Isao, YAJI Kentaro, YAJI Kentaro, YAMASAKI Takayuki, YAMASAKI Takayuki, FUKUDA Takeo, NOGUCHI Motokazu, TAKEYAMA Norihide, KANAI Yoshikazu, YAMAMURO Tomoyasu, YAMAMURO Tomoyasu
    Publications of the Astronomical Society of Japan 70(4) 58.1-58.17 2018年8月1日  査読有り
  • Kentaro Yaji
    Communicating Astronomy with the Public Conference 2018 114-115 2018年4月  査読有り筆頭著者
  • Takeshi Imamura, Munetoshi Tokumaru, Hiroaki Isobe, Daikou Shiota, Hiroki Ando, Mayu Miyamoto, Tomoaki Toda, Bernd Haeusler, Martin Paetzold, Alexander Nabatov, Ayumi Asai, Kentaro Yaji, Manabu Yamada, Masato Nakamura
    ASTROPHYSICAL JOURNAL 788(2) 117 2014年6月  査読有り
    Radio scintillation observations have been unable to probe flow speeds in the low corona where the scattering of radio waves is exceedingly strong. Here we estimate outflow speeds continuously from the vicinity of the Sun to the outer corona (heliocentric distances of 1.5-20.5 solar radii) by applying the strong scattering theory to radio scintillations for the first time, using the Akatsuki spacecraft as the radio source. Small, nonzero outflow speeds were observed over a wide latitudinal range in the quiet-Sun low corona, suggesting that the supply of plasma from closed loops to the solar wind occurs over an extended area. The existence of power-law density fluctuations down to the scale of 100 m was suggested, which is indicative of well-developed turbulence which can play a key role in heating the corona. At higher altitudes, a rapid acceleration typical of radial open fields is observed, and the temperatures derived from the speed profile show a distinct maximum in the outer corona. This study opened up a possibility of observing detailed flow structures near the Sun from a vast amount of existing interplanetary scintillation data.
  • K. Yaji
    COSPAR Colloquia Series 13(C) 121-122 2002年  
    In Japan, solar telescopes are now operated in more than fifty astronomical educational facilities, for example, public observatories and science museums. Since most of these have the capability of observing the sun in Hα, active chromospheric phenomena such as solar flares and prominences are often presented to the public there. Though these telescopes must be mainly used for education and public outreach, they have good enough performance to contribute to professional solar research. The staff in most of the facilities don't know well how best to observe the sun and how to understand solar phenomena. We started two efforts in order to support their solar observations. One is the administration of the "Solar Telescope Mailing List" (solnet ML). The other is the arrangement of the "Solar Telescope Workshops". © 2002 Elsevier B.V. All rights reserved.
  • M Nishio, K Yaji, T Kosugi, H Nakajima, T Sakurai
    ASTROPHYSICAL JOURNAL 489(2) 976-991 1997年11月  査読有り
    The results of an analysis of 14 impulsive solar flares, observed simultaneously with microwave and X-ray imaging instruments, are presented. From the relative locations of microwave, hard X-ray, and soft X-ray sources, we have found that in 10 of the 14, at least two loops are involved. Typical sizes of the two loops differ; one is typically less than or equal to 20 '' and the other 30 ''-80 ''. Microwave emission is detected from both loops, while hard X-ray emission is preferentially radiated from the shorter of the two loops. The shorter loop is brighter than the longer loop in soft X-rays. However, intensity variations of microwaves from the two loops are similar. These observations, together with comparisons of the microwave/X-ray images with photospheric magnetograms, suggest that in the majority of impulsive flare events two loops interact with each other, releasing magnetic energy and producing energetic electrons. The observations are therefore consistent with the emerging flux model of flares.
  • N Nitta, K Yaji
    ASTROPHYSICAL JOURNAL 484(2) 927-& 1997年8月  査読有り
    We report the first solar flare for which direct X-ray imaging (with focusing optics) has shown the location of superhot (T similar to 30 MK) plasma. This hare consists of two separate loop structures. The smaller structure dominates the soft X-ray emission, but the longer structure develops with persistently higher temperatures, which overlaps with low-energy hard X-ray sources with very soft spectra. Using a two-temperature model, we describe how the soft X-ray images lead to the inference of superhot temperatures in the latter structure, as we combine three broadband measurements at slightly different effective wavelengths.

主要なMISC

 74

主要な書籍等出版物

 4
  • 矢治健太郎 (担当:分担執筆, 範囲:Public Outreach and Education Activities of Solar Mission Hinode in Japan)
    Springer 2018年3月 (ISBN: 9789811077425)
  • 矢治健太郎
    PHP研究所 2009年6月 (ISBN: 9784569707648)
    太陽とはどんな星なのか、太陽活動と地球の関係、フレアが地球に与える影響、現在の太陽研究事情など、意外に知られていない太陽の不思議をわかりやすく紹介しています。 コラムにはちょっと私のこだわりなんかも入れています。わたしの日頃の講演や講義の内容を一般向けにまとめた内容となっています。

主要な講演・口頭発表等

 49
  • 矢治健太郎, 下条圭美, 時政典孝, 鈴木大輔
    日本天文学会2023年春季年会 2023年3月14日 日本天文学会
  • Kentaro Yaji
    Global Hands-On Universe Conference 2021年8月24日 Global Hands-On Universe
    Solar observation satellite "Hinode" was launched in 2006.   This year marks the 15th year of launch. It has encouraged the use of Hinode data for not only  research but also education.  "Let's Look at the Sun with Hinode" is a joint observation campaign with  high and junior high school students. Called “With Hinode!” for short, it is highly evaluated as a unique activity. In Japan, the students have high acitiviy of solar observation in the extracurriicular class. This  joint observation  started in 2010 and we have been carried out  for 11 years. The students compare Hinode data with their observation data  and deeply study the sun.  Additionally, they held presentations at their schools’ festivals, prefectural science contests, and junior sessions in the astronomical society’s annual meeting. This year, "With Hinode" is carried out from Aug.2  to Aug.7. In July,17 we gave a previous online tutirial  to the partipant students for this joint observations. In this talk, we reflect  " With  Hinode" to date and report this year's observation results.
  • Kentaro Yaji, Masumi Shimojo
    The ninth Communicating Astronomy with the Public Conference (CAP) 2021 2021年5月24日
    The sun is the most popular star for us. Therefore, the public have high interests in the solar activity as ever. In fact, in the previous 24th solar maximum(2009-2020), when the solar eclipse, the big sunspots, and the huge solar flare occurred, the public including mass media pay intense attention to such solar phenomena. In addition, the public have high interests in the relation between the solar activity and climate change on the earth. Since solar observation satellite "Hinode" was launched in 2006 and even now, the observation data has been used on the astronomy communication scene in various ways. After that, STEREO and SDO were also launched and similar activity have been done on the astronomy communication scene. In Japan, with these solar observation data, we have been promoting public use of Hinode data working group and joint observations with high/junior high schools. Teaching materials with Hinode data have been developed and used in the class room practice. These activities have drawn the attention of solar researchers at home and abroad. From now on, the next 25th solar cycle is coming, the solar activity will be active again. New solar observation spacecraft, Parker Solar Probe (PSP) and Solar Orbiter were already launched towards the inner heliosphere. PSP has already new findings about the interesting structures of solar wind as initial results. DKIST is also operated as the solar ground-based solar observatory. In Japan, Solar_C_EUVST is planned as a successor of Hinode. It is expected that we can obtain new high spatial resolution data and new information of the heliosphere  from these current and future observation instruments next by next. In particular, the solar phenomena as solar flares, CMEs, solar wind have influences on the near-earth space. If the solar research make progress with the new instruments in future, we can deeply understand space weather relating our life. Moreover, that might lead to new knowledge between solar activity and climate change. Thus we would obtain the opportunities to communicate the new solar astronomy with the pubic. In this virtual conference, we would like to opportunities for not only reflecting our and others’ astronomical communication to date but also generating new method and idea based on the new coming solar data in the future. In addition, we would also communicate the relation between the solar activity and climate change among the participants.
  • Kentaro Yaji
    The 5th Asia Pacific Solar Physics Meeting (APSPM) 2020年2月7日 The 5th Asia Pacific Solar Physics Meeting (APSPM)  招待有り
    The sun is very popular objects for us and the public are very interested in the solar activity. For example, when big sunspots appear and a huge flare occurs, the public including mass media pay intense attentions to such solar phenomena. As the back ground of science/astronomy education/outreach in Japan, some specific points are as below. 1. The sun is surely studied in science class of formal education. 2. Extracurricular activities of natural science in high and junior high schools. 3. There are many science museums, planetariums, and  public observatories. 4. Amateur astronomers have high activities. Since Hinode launched in 2006, the observation data have been used in various ways on the scene of astronomical education and outreach. In this talk, I  focus two specific activities with use of Hinode observation data. One is Hinode Data Use Working Group, which contributes in outreach at the early phase of Hinode observations.  The other is “Let’s Look at the Sun with Hinode together”, which is simultaneous observation campaign  with high  and junior high  school students. This is highly evaluated as a unique activity and continue for ten years. The students compare Hinode data with their own observation data and deeply  understand the sun.   In addition, I introduce  outreach activities in Institute for Fusion Science where I am working now.
  • 矢治健太郎
    Thai-Asian Astronomy, Star-Gazing & Cultural Exchange 2015 2015年1月13日  招待有り
  • Kentaro Yaji, PAONET working, group for, Public Use for, Hinode Data
    Communicating Astronomy with the Public 2010 2010年3月16日

主要な担当経験のある科目(授業)

 15

主要な共同研究・競争的資金等の研究課題

 27

学術貢献活動

 15

主要な社会貢献活動

 47